The Choice of Jack and Jennet
Donkeys can suffer from many conformation defects (See Conformation Defects). These are largely due to generations of indiscriminate breeding which have promoted and accentuated such conformation defects as crooked legs, narrow chests and jaw defects. The novice breeder should visit as many donkey breeders and donkey shows as possible to study and understand donkeys as work animals before investing in breeding stock.
The purpose of registration is to record individual animals so that their type and ancestry are known. Breeders who keep good records are likely to be helpful in getting the novice breeder established. Such records, as well as the opportunity to view both parents of a sale animal, are a distinct advantage when purchasing stock.
Methods of Breeding Pasture breeding
The simplest way to bred donkeys is to turn a jack out with a group of jennets and allow them to breed naturally. However, there are some possible disadvantages:
- A jack that is not in excellent condition may not successfully breed all the jennets.
- Risk of injury to the jack by aggressive jennets, or vice versa.
- Risk of injury to foals in the herd. The jabk may try to kill any jack foal born.
- Risk of infection being spread in an uncontrolled situation.
- Difficulty in determining dates of breeding and foaling dates unless the donkeys are closely observed.
A jennet can be placed in a breeding chute or stall and bred with a jack that is controlled by a handler. Advantages are:
- Minimal risk of injury to jack and The foal can be placed close by so the jennet is not worried about her offspring.
- The jack’s energy can be conserved and is not wasted chasing jennets.
- Risk of disease is reduced as both jack and jennet can be washed thoroughly before breeding.
- Exact dates for breeding can be recorded and dates for foaling can be predicted.
Disadvantages of this method are the requirement of extra care, handling, and facilities for regular teasing, and breeding of the jennets. Some jacks are slow breeders, so the process can be time consuming.
Semen collected from a jack can be used to artificially inseminate one or more jennets. The main advantages of this technique are the lowered risk of infection, and the possibility breeding more jennets. The disbdvantages of Al for many small breeders is the costs involved for a trained technician, or the courses and purchase of equipment to establish them in equine Al.
Jacks can be precocious at an early age, and young jennets often show their first heat cycles early in the yearling year. However, it is unwise to breed donkeys that are less than three-years-old because they mature slowly. An immature jennet that becomes pregnant may suffer permanent damage to the skeletal and muscular system and may produce foals with congenital malformations. Physically immature jennets may also lack the maturity to be good mothers.
Signs of Estrus
Jennets do not normally show estrus throughout the winter months, but often start to show signs of estrus in March, and then continue to cycle normally every 21 to 28 days until conception occurs, or towards year end in November or December. When in heat the jennet will lay her ears back, and repeatedly open and close the mouth in a mouthing reflex, sometimes drooling. The jennet will squat to urinate more frequently and bray more often than normal.